Corneal curvature instrument

Abstract

A corneal curvature instrument includes a cylindrical housing for accommodating the following parts of the corneal curvature instrument, a light source fixed near one end of the cylindrical housing, aplacido disc arranged in front of the light source and used for converting light emitted by the light source into light beams distributed in a concentric circle pattern, and a lens disposed in frontof the placido disc and used for magnifying and projecting the light passing through the placido disc onto the corneal surface to image a placido ring. By utilizing a lens imaging principle, the placido disc is projected to the surface of the cornea, a complete placido ring is formed on the surface of the cornea, the placido disc is hung on one side of a microscope, the placido ring projected to the corneal surface can be observed in an observation field of the microscope, direct contact with an eyeball is avoided, and operation errors caused by corneal deformation caused by compression produced on the eyeball are prevented. The operation space is provided for the operation, the corneal curvature condition can be observed in real time in the suturing process, the tightness of a sutures canbe adjusted instantly, the operation time is saved, and the risk in the operation is reduced.

Description

technical field [0001] The invention relates to the technical field of keratometers, in particular to a keratometer. Background technique [0002] The cornea is an important structure of the eye imaging system, and changes in the curvature of the cornea can seriously affect vision. For corneal transplantation, surgery or trauma, etc., the cornea needs to be sutured, and the tightness of the suture will affect the curvature of the cornea, thereby affecting the vision of the patient. At present, it is not clear whether the suture tightness will change the corneal curvature during the suture process. Therefore, it often causes a large difference in the corneal curvature after suture. If the effect of suture tightness on corneal curvature can be determined and adjusted during surgery, it is very important to improve the visual quality of patients after surgery. [0003] At present, there are corneal topography and keratometer to measure the curvature of the cornea clinically. ...

AI Technical Summary

Problems solved by technology

[0006] (2) Direct light projection is used without lens focusing;

[0007] (3) In order to measure the curvature of the cornea at different depths, it needs to be rotated, resulting in a large volume of equipment;

[0009] (5) The incident distance (the distance from the placido disc to the cornea) is fixed and not adjustable;

[0010] (6) The angle of incidence is fixed and cannot be adjusted, and must be projected directly to the cornea;

[0011] Disadvantages of corneal topography: large volume; must sit for inspection, cannot be set in the operating room, so it cannot be used during surgery (it cannot be used after corneal suture during surgery)

[0015] (1) It does not have a light source, and can only reflect the light of the microscope to the surface of the cornea. The light intensity is small and the image is not clear

[0016] (2) Because of the use of reflected light, direct contact with the cornea is required during use, and it cannot be used in real time during surgery to monitor changes in corneal curvature, and can only be used after suturing

If there is no direct contact with the cornea, the reflected light will be reflected in other directions and cannot be accurately projected onto the cornea, resulting in no imaging

[0017] (3) Since reflected light is used, complete placido rings (concentric circles) cannot be formed

[0018] The corneal topography is too large, and the patient is examined in a sitting position, which cannot be applied to patients lying flat during the operation, and the keratometer cannot observe the overall curvature of the cornea in real time

[0019] At present, a corneal projection made of metal is available in the operation. Its defect is that the observation is very unclear. It is difficult to project a complete placido ring on the corneal surface, and it cannot be observed in real time. It can only be removed after the suture is completed. Stick it on the surface of the cornea and observe it by projection. If it is too loose or too tight, the original suture can only be removed and sutured again. According to experience, the tightness can be mastered, and then observed again. If necessary, the above operation needs to be repeated, which is time-consuming and the effect is poor.

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